News reporting of preprints became commonplace during the COVID-19 pandemic, yet the extent to which the public understands what preprints are is unclear. We sought to fill this gap by conducting a content analysis of 1,702 definitions of the term ‘preprint’ that were generated by the US general population and college students. We found that only about two in five people were able to define preprints in ways that align with scholarly conceptualizations of the term, although participants provided a wide array of “other” definitions of preprints that suggest at least a partial understanding of the term. Providing participants with a definition of preprints in a news article helped improve preprint understanding for the student sample, but not for the general population. Our findings shed light on misperceptions that the public has about preprints, underscoring the importance of better education about the nature of preprint research.